London - British investigators said on Friday they were probing the licence held by the pilot of the small plane carrying Premier League player Emiliano Sala that went missing over the Channel this week.
The light aircraft transporting the 28-year-old striker, who signed for Cardiff City last weekend, disappeared from radar around 20 kilometres (12 miles) north of Guernsey on Monday night.
The local coastguard on Wednesday named the pilot, the only other person in the plane, as David Ibbotson - a 60-year-old married father of three from northern England, according to reports.
A spokesman for Britain's Air Accidents Investigation Branch (AAIB) told AFP that his licence would be reviewed as part of its probe into the plane's disappearance.
"We would look at operational aspects of the flight and that would include licensing," he said.
"Our purpose is not to apportion blame or liability. Our purpose is to establish the cause of an accident," the spokesman added.
Ibbotson reportedly told a friend via social media shortly before take-off that he was "a bit rusty" with some of the controls on the plane.
Sala, who signed on Saturday from French club Nantes for a reported fee of €17 million, was flying to Cardiff in a single-engine Piper PA-46 Malibu aircraft registered in the United States.
According to a US Federal Aviation Administration database, Ibbotson held a British private pilot licence which provided the basis for a similar certificate issued there in 2014 permitting him to fly single-engine planes.
Britain's Civil Aviation Authority, which issues UK licences in accordance with European Union regulations, said Friday it could not "confirm the type of licence held by Ibbotson".
According to EU aviation rules posted online by the CAA, a private pilot licence is "for recreational flying only".
"You aren't allowed to be paid for any flying you do using one, apart from some flight instructor work," its guidance states, noting pilots receiving payment need a commercial license.
Rescue workers formally called off the search for the missing plane on Thursday, prompting Sala's sister to make a desperate plea for its resumption.
"We are not going to stop looking, we are never going to stop," Romina Sala told media in Cardiff. "Emi and the pilot are here and we can't leave them."
The family's calls for the search to recommence were echoed by Lionel Messi and other players including fellow Argentines Gonzalo Higuain, Nicolas Otamendi and Lucas Biglia.
"While there is the possibility, a shred of hope, we ask that you please #NoDejenDeBuscar (don't stop searching) for Emiliano," said Barcelona attacker Messi.
Nantes coach Vahid Halilhodzic said Friday that it was "disgraceful" that the search had been called off as he knew "in his heart" that Sala was still alive.
"It's disgusting to leave the situation like that," Halilhodzic told reporters.
Cardiff chief executive Ken Choo added that "we still hope that the search mission can continue and we could locate Emiliano
The Premier League announced on Thursday that there would be a "moment of silent reflection" in tribute to Sala before next week's fixtures.
However the French League said they had no plans for a similar commemoration at this week's Ligue 1 matches. League president Nathalie Boy de la Tour said the decision was taken out of respect for the "desires of Emiliano Sala's parents and loved ones" who believed he could still be alive.